Containers and interlocked pack thereof



April 9, 1963 E. F. KOELSCH 3,084,830

CONTAINERS AND INTERLOCKED PACK THEREOF Filed Nov. '7, 1960 4 Sheets-Sheet 1 r ""W' WWI /5 gggj m /3 U) "MUM U EMERY E KOELSCH INVENTOR HUEBNER 8 WORREL 4 147TO/PNEYS Fe. 3. "MM

Apnl 9, 1963 E. F. KOELSCH CONTAINERS AND INTERLOCKED PACK THEREOF 4 Sheets-Sheet 2 Filed Nov. '7, 1960 70 I f a EMERV E KOELSCH A TTO/P/VEKS April 9, 1963 E. F. KOELSCH ,0 4 8 CONTAINERS AND INTERLOCKED PACK THEREOF Filed Nov. '7, 1960 4 Sheets-Sheet 5 EMERV r." mast/v IN VE N 70/? HUE'BNER 8 WORREL i ATTORNEYS m/W'M A nl 9, 1963 E. F. KOELSCH 3,084,830

CONTAINERS AND INTERLOCKED PACK THEREOF Filed Nov. '7, 1960 4 Sheets-Sheet 4 /36 a? w m EMERY E KOELSCH l/vvs/vmk HUEBNER & WORREL A77'ORNEKS United States Patent 3,084,830 CONTAINERS AND INTERLGCKED PACK THEREGF Emery F. Koelsch, Fresno, Califi, assignor to Royal Jet, a division of Royal Industries, Inc., Alhambra, Calih, a corporation of California Filed Nov. 7, 196%, Ser. No. 67,692 12 Claims. (Cl. 22.097)

The present invention relates to containers for housing articles for shipment, storage, and the like and to an interlocked pack of such containers.

The handling and shipment of manufactured articles and produce have long required specialized containers. Such containers have frequently been formed of wood or fiberboard and have been disposable. With the increasing complexity and delicacy of articles intended for shipment, such as rocket components, electronic gear and the like, the containers have been required correspondingly to improve to meet their increasingly exacting requirements. The resultant development has lead to the provision of re-usable metal shipping and storage containers of the general type to which the present invention relates.

However, previous re-usable containers have been subject to certain difliculties which the present invention is believed to overcome. They have generally been insufficiently adaptable to varied size and shape requirements. In many instances, they have been complex to fabricate. In their larger sizes, they have been cumbersome to handle. Further, they have made no provision for convenient interlocked association in packs so that a plurality of such containers could conveniently be stacked and shipped as a handling unit.

An object of the present invention is, therefore, to provide an improved shipping container and interlocked pack thereof.

.Another object of the present invention .is to provide an improved container adapted for interlocking stacked association with similar containers of the same or differing sizes.

Another object is to provide a sheet metal container having identical top and bottom walls adapted for interlocked stacked association with similar containers to resist relative transverse shifting.

Another object is to provide interlocking containers of a common form but of different capacities to accommodate contained articles of various sizes which it is desired to ship in a unitary pack for subsequent assembly or other association.

Another object is to provide sheet metal containers suited to stacked association in which the containers provide nested bottom and top walls to resist lateral shifting and end and side Walls marginally extended over the top walls and marginally extended under the bottom walls, said marginally extended end and side walls acting as spacers between adjacent top and bottom walls of stacked containers.

Other objects and advantages of the present invention will become apparent in the following description in the specification.

In the drawings:

FIG. 1 is a top plan view of a container embodying the principles of the present invention.

FIG. 2 is a side elevation of the container of FIG. 1 including a fragmentary top portion of an identical container with portions broken away to show their interlocked nesting relation.

FIG. 3 is a fragmentary end elevation of the containers of FIG. 2 with portions broken away for illustrative convenience.

FIG. 4 is a somewhat enlarged fragmentary section taken on line 44 of FIG. 2.

3,84,83h Patented Apr. 9, 1953 FIG. 5.

FIG. 7 is an exploded isometric view of the interlocking surfaces between the top and second layers of containers in FIG. 5.

FIG. 8 is an exploded isometric view showing the interlocking surfaces between the containers of the second and lower layers thereof in FIG. 5.

FIG. 9 is a somewhat enlarged section showing a double frusto-conical form of locking means associated with the top and bottom walls of a pair of the containers of FIG. 5.

FIG. 10 is an assembled view of the structure shown in FIG. 9 with the locking means rigidly mounted in one of the container walls.

FIG. 11 is a plan view of the locking means of FIG. 10 with one container wall removed for illustrative convenience.

FIG. 12 is an isometric view of a double frustopyramidal form of locking device.

FIG. 13 is an isometric view of a further frusto-conical form of the locking device.

FIG. 14 is an isometric view of a further frustopyramidal locking device.

Referring more particularly to the drawings, a container embodying the principles of the present invention is indicated generally at 10. The container includes a top wall 11 of light weight sheet material and an opposed similar bottom wall 12. The top and bottom walls are interconnected by right-angularly disposed opposite end Walls 13 continuously extending to form opposite side walls 14. The top, end, side and bottom walls enclose a compartment which may be made accessible through any suitable opening. In the present container, the side and end walls are made separable along a plane 15 midway between the top and bottom walls. The separable top and bottom portions of the end and side walls are releasably retained in closed relation by a plurality of latches of any suitable form, indicated at 16. A pair of handles 17 are also preferably provided on the exterior of the side walls 14 whereby the container may be readily lifted and carried.

The top wall 11 includes a pair of spaced, longitudinally extended, frustum shaped tongue members 18 projecting outwardly from the top '11. The tongues terminate at opposite ends 19 short of the marginal ends 13 of the container and are substantially parallel to each other and to the adjacent side Walls 14. As best shown in FIGS. 2 and 3, the bottom wall of the container is provided with identical frustum shaped, spaced, elongated, substantially parallel grooves 2i) having oposite ends 21. The grooves are adapted to receive the tongues 18 when the bottom wall 12 of one container is stacked in superimposed relation upon the top wall 11. A feature of the invention is the provision of substantially identical top and bottom Walls in the described containers having unique advantage in the formation of packs of said containers, as will soon become apparent.

While the bottom wall 12 and grooves 26 of one container 10 may be directly in contact with the top wall 11 and tongues 18 of another container of a stack, as shown in FIGS. 2 and 3, the preferred form of the container, as best shown in FIG. 4, provides minute spacing between the top 11 and bottom 12 walls, respectively. When the containers 10 are stacked, the grooves 20 of the bottom wall 12 of the upper container fit over the upwardly disposed tongues 18 of the top wall 11 of the lower container. This nested association effectively resists inadvertent lateral shifting of the containers. However, in the preferred form another feature is worthy of note. In each such container, the end walls 13 and the side walls 14 extend inwardly over the marginal edges of the top wall '11. and inwardly under the marginal edges of the bottom wall 12. The end and side walls are weldably or otherwise rigidly secured to their top and bottom walls. Not onlydoes such-association assure the formation of a container of desirable strength and durability in relation to thematerial employed but, as shown in FIG. 4, the inwardly extended portions of the end and side walls of the upper container rest on the inwardly extended portions of the end and side walls of the lower container, said inwardly extended portions serving as spacers facilitating nesting of the top and bottom walls 11 and 12 and transmitting the load of such stacked association of containers to said end walls and side walls, where it is most effectively borne, while shielding the top and bottom walls from such load where it is most likely to be of crushing effect.

As stated, the top and bottom walls 11 and 12 are substantially identical and are conveniently form-ed by the same dies in stamping operations. In the form of the containers shown in FIGS. 1 through 4, said walls are mounted in their respective containers so as to provide the mating tongues and grooves 13 and 2t). As shown in PTGS. through 8, the top and bottom panels may be ettectively employed to provide both upwardly and downwardly disposed grooves which are juxtapositioned when the containers are stacked.

A stack of such containers is shown in FIG. 5 and illustratively includes a pair of elongated, substantially rectangular, bottom containers 22 and 23. Each of the containers includes a top wall 24 and 25, a bottom wall 26 and 27, a pair of opposite end walls 28 and 29, and a pair of opposite side walls 36 and 31 respectively. The end and side walls are weldably or otherwise rigidly secured to their top and bottom walls in a manner similar to that previously explained with regard to the form of the containers in FIGS. 1 through 4. In each of the top and bottom walls of the containers is disposed a pair of identical, spaced, parallel, elongated frustum-shaped grooves 32 and 33 and 34 and 35 respectively. As best shown in FIG. 8 the grooves are disposed in substantially parallel relation to the side walls 30 and 31 and terminate in opposite ends short of their respective end Walls 28 and 29.

The intermediate layer of the pack includes a pair of elongated substantially rectangular containers 40 and 41. Each of the containers includes a bottom wall 42 and 43 and a top wall 44 and 45, respectively, which are interconnected by a pair of opposite side walls 46 and 47 and a pair of opposite end Walls 48 and 49 respectively. The bottom walls of the containers at and 41 individually include a pair of identical, spaced, parallel, longitudinally extended, frustum-shaped grooves 50 and 51 and 52 and 53 respectively, which extend in substantially parallel relation to the side walls of the containers and terminate in ends short of their respective end walls 48 and 49. The bottom walls :2 and 43 are adapted to overlie the top walls of the bottom containers 22 and 23 in the stack with the grooves 44, 45, as, and 47 being disposed in rightangular, superimposed relation over the grooves 32, 33, 34 and 35 of the bottom containers. The top walls of the containers 40 and 4-1 individually include a pair of identical, spaced, parallel, longitudinally extended grooves 54 and 55, and '56 and 57 which open upwardly in the stack for a purpose soon to be described.

The top layer of containers forming the pack of FIG. 5 includes a centrally disposed substantially rectangular container 6% which illustratively extends the full width of the combined transverse dimension of the containers 4i? and 4 1. The top layer further includes a plurality of outwardly disposed containers 6T, 62, 63 and 64 which are disposed upwardly adjacent to the respective end walls 48 and as of the containers 4t) and 4 and combine to extend the full transverse width thereof. The container 6%) includes a bottom wall 65, a top wall 66, interconnected by a pair of opposite side walls 67 and a pair of opposite end walls 68. As best shown in MG. 7, the top and bottorn walls individually include a pair of identical, spaced parallel, longitudinal extended frustum-shaped grooves 69 and 70. The grooves 69 and 70 are disposed in rightangular relation with respect to the grooves 54, 55, 56, and 57 in the top walls of the containers 40 and 41 when the containers are stacked in the superimposed relation shown in FIG. 5. Similarly, the containers 61 and 62 individually include a bottom wall 71 and 72, a top wall '73 and 74, a pair of opposite side walls 75 and 76 and a pair of opposite end walls '77 and 78, respectively. The top and bottom walls each include a pair of identical, spaced, parallel, frustum-shaped grooves 79 and 80, and 81 and 82 therein which extend substantially parallel to their respective side walls and to the grooves 69 and '70 in the container 61 When the bottom walls 71 and 72 of the containers 61 and 62 are superimposed on the top walls 44 and 4 5 of the containers 4t} and 41, the respective grooves therein are thereby disposed in right-angular relation. The opposite out-er containers 63 and 64 individually provide a bottom wall 35 and 86, a top wall 87 and 88, a pair of opposite side walls 89 and 9t)- and a pair of opposite end walls 91 and 92 respectively, interconnected in the afore described manner. The top and bottom walls provide a pair of identical, spaced, parallel -frustum-shaped grooves 9394 and 95-%, respectively which extend in the same direction as the grooves in the containers 4% and 41.

A plurality of double frusto-conically shaped blocks or boss members, generally identified by the numeral 100, are adapted to be received between the grooves of adjacent container-s. As shown, in FIG. 9 the frusturn-shaped groove 54 of the container 40 is disposed in close juxtaposition to the inverted frustum-shaped groove 89 of the overlying container 63. The grooves so arranged, are adapted to receive therebetween one of the blocks 100. The block can be made solid or formed in halves of a suitable sheet material which are then joined as by spot welding along a centrally disposed line indicated at 101. When the wall 85 is restedon the wall 44 the block 100, sandwiched between the grooves, prevents relative lateral shifting of the containers. The single block can not, however, prevent longitudinal shifting when overlying grooves extend in the same direction. This problem is overcome by rigidly securing the block to one or the .grooves, as by welding, such as shown in FIG. 10. With the block so secured, it abuts the end of the groove 93 as in FIG. 11 and prevents shifting of the adjacent wall in one longitudinal direction. A similar arrangement is then employed atthe opposite end of the groove 93 to prevent shifting in the opposite direction.

In FIGS. 6 and 7 a plurality of the blocks 1% are disposed in the grooves in the containers 60,61, 62, 63 and 64 and extend into the grooves in the containers 40 and 41. The blocks are indicated by doted circles in 'FIG. 6 as being disposed at the ends of the grooves and at such positions where the superimposed grooves cross or overlap the grooves therebelow. As shown, a pair of the blocks 10%) are positioned at spaced points designated by the numeral to abut the end of the grooves 69 and 70 and the inner side of the groove 57 to prevent shifting of the'container 60' inone lateral direction, downwardly as viewed, relative to the containers 4!} and all. A similar arrangement of blocks is disposed at the opposite ends of the grooves 69 and 70 wherein a pair of the blocks are positioned at 111 in the groove 54 to prevent shifting of such containers in the other lateral direction, upwardly as viewed. Additional blocks indicated at positions 112 are extended between the grooves 69 and 70 and the inner grooves 55 and 56 of the containers 49 and 41 at their points of intersection for additional stability. So mounted, the containers 6%) may still be longitudinally shifted relative to the containers 40 and 41 against the frictional drag imposed by the blocks in the grooves. Such movement, however, is restricted in one direction by abutrnentwith the outer containers 61 and 62 and in the other direction by abutment with the opposite outer containers 6'3 and 64-, when said outer containers are locked in position. The containers 61 and 62 are held against movement to the right as viewed in 'FIG. 6, by the extension or" a plurality of the blocks between the grooves 79 and '81 and the grooves 54, 55, 56 and 57 in the containers 40 and 41 as indicated at 113 and 114.

The grooves in the containers 63 and 64 however extend substantially parallel to the grooves 54, 55, 56 and 57 in containers 40 and 41. In order to retain the containers 63 and 64 in the pack against sliding movement to the left, as viewed in FIG. 6, it is necessary rigidly to secure the blocks indicated at 115 and 116 in the grooves of their respective upper containers in the manner previously described and shown in FIG. 10. The blocks 115 and 116 are individually welded or otherwise rigidly mounted in the outer ends of the grooves 93, 94, 95, and 96 in positions so as to abut the ends of the grooves 54, 55, 56 and 57 in the containers 40 and 41. Such arrangement thereby prevents shifting of the containers 63 and 64 to the left, as viewed in FIG. 6, and in turn dependably retains the container 60 in the pack against the containers 61 and 62.

This may also be accomplished by rigidly mounting the blocks 100 in the grooves 54, 55, 56, and '57 of the containers 40 and 41 at predetermined positions indicated at 117 and 118 respectively. The blocks are so positioned to extend upwardly into the corresponding grooves in the bottom walls of the containers 63 and 64 to abut the inner end thereof which, as before, limit movement of the upper containers to the left, as viewed in FIG. 6.

In 'FIG. 8 the connection between the bottom and intermediate layer of containers is shown having a plurality of the blocks 100 disposed therebetween in a manner similar to that just described for the top layer of containers in the pack. In this case, however, all the grooves in the bottom wall of the overlying containers 4t} and 41 extend in transverse overlying relation to the grooves in the top Walls of the bottom containers 22 and 23. With such arrangement, it is only necessary to position the blocks adjacent to the four outer corners of the pack to prevent relative lateral shifting of the containers in any horizontal planular direction. The blocks, being so disposed, are indicated at 120, 121, 122, and 123 in a manner to abut the overlapping ends of the overlying and underlying grooves. Other blocks may be disposed in the inner grooves of the containers merely for additional stability. In this arrangement, therefore, relative lateral shifting of the containers is resisted Without requiring the welding or otherwise rigid securing of the blocks to either of the overlying or underlying containers by the abutment of said four blocks with the ends of their grooves.

While the blocks 100 represent a desired embodiment of the container locking means, other forms can be employed in accordance with the invention. Such forms are typified by the structures illustrated in FIGS. 12 through 14. An equivalent block 130 is shown in FIG. 12 as having a double truste -pyramidal shape which, as in the preferred embodiment, can be formed in a solid block or manufactured by stamping the halves from sheet metal or the like and spot-welding them together at a joining line indicated at 131.

Another equivalent embodiment of the double frustoconical lock is provided by a single frusto-conically shaped locking device shown at 134 in FIG. 13. This embodiment includes a central boss 135 having a pair of integral tabs 136 oppositely, outwardly extended from the lower portion thereof, which are adapted to be received and rigidly mounted, as by welding or the like, on the bottom wall of the grooves in the containers. This locking means has a pair of oppositely disposed notches 137 which extend through the lower portion of the boss between the tabs to provide suitable openings through which the diverging walls of the frusturn-shaped grooves extend. The single frusto-conical locking device 134 presents an outwardly extended boss identical to the double frusto-conical design when installed in a groove in the above described manner. This embodiment can be manufactured from a single sheet of metal or the like and requires no additional assembling operation.

A further equivalent embodiment of the locking device is provided by a single frusto-pyramidal form indicated at 140 in FIG. -14. This form may also be fabricated from a single sheet of material without additional assembly procedures. The locking means 140 includes a central boss 14 1 having a pair of integral tabs 142 extending oppositely outwardly from the lower portion of the boss which are adapted to be welded or otherwise rigidly secured to the bottom wall of the grooves. A pair of opposite side walls 143, integral with the upper portion of the boss .141 extend divergently downwardly therefrom for fitted engagement against the walls of a downwardly disposed groove of the container.

Operation The operation of the described embodiments of the subject invention is believed to be readily apparentand is briefly summarized at this point. The first form of the present invention permits a plurality of the described containers to be stacked in vertically aligned relation. In so stacking, the frustum-shaped tongues -18 in the top walls of the lower containers are adapted to be received in interlocking relation in the frustum-shaped grooves 20 in the bottom wall of the upper container. The tongues and grooves are minutely vertically spaced by the inwardly curving side and end walls 13 and 14, respectively, which function to support the full weight imposed on the lower containers by the superimposed upper containers. The tongues and grooves are operative to resist relative lateral or longitudinal shifting of the containers. The support of the weight by the side walls and the end walls and the resistance to lateral shifting by the nested top and bottom walls enables a greater number of containers to be stacked in a more dependable arrangement than heretofore possible. It is further noted that the top and bottom walls are substantially identical which enables a single stamping die to be employed for the forming operation. So formed, the walls are reversible to provide either the top or the bottom of the container.

The second form of the invention enables a plurality of containers of diiferent shapes and sizes to be stacked in superimposed interlocking relation, as for unitary handling. These containers are distinguished from the containers of the first form by the provision of frustumshaped concave groooves in both the top and bottom walls thereof. -As shown in FIGS. 5 and 6 a plurality of such containers are adapted to form a pack wherein each layer of the pack includes two or more containers. In order to retain such a pack in unitary assembly, a plurality of the blocks are disposed between adjacent overlying and underlying containers to extend into their respective overlapping grooves. Where the grooves of the adjacent superimposed containers extend in rightangular relation to each other, as shown in FIG. 8, the blocks may be positioned freely at the corners of the pack to abut the ends of the overlapping grooves and thereby to resist relative horizontal movement of the containers. In the event, however, the grooves of adjacent superimposed containers extend in parallel relation to each other, the blocks 100 are rigidly mounted as by welding or the like, in either the upper or the lower grooves. In either case, the blocks abut the ends of the grooves into which they are extended from their welded ends to prevent relative shifting of the containers. All of the blocks can, of course, be rigidly mounted in the grooves, if so desired, to prevent their being lost. As previously described, this is not entirely necessary for their successful operation in the pack.

From the foregoing, it is apparent that the blocks in association with the described containers enable the pack to be formed quickly and easily with the containers in dependable association. The pack readily incorporates containers of varied sizes and proportions to accommodate articles housed thereby which it is desired to ship and/ or store in close proximity for subsequent assembly or other use. The blocks and containers are economical to produce and are salvageable for re-use.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

Having described my invention, What I claim as new and desire to secure by Letters Patent is:

1. In a pack of containers, the combination of a plurality of containers stacked in superimposed layers whereby there are relatively upper and lower containers, each of the upper containers having a lower wall supported on the lower containers and providing a pair of substantially parallel grooves therein, and each of the lower containers having an upper wall including means upwardly extended therefrom, said means of the lower containers being in fitted engagement in the grooves of the bottom walls of the upper containers.

2. A pack of containers comprising a plurality of substantially rectangular containers arranged in contiguous horizontal relation :and in superimposed layers whereby there are relatively upper and lower containers, the upper containers having lower walls each providing substan tially parallel grooves extended longitudinally thereof having closed opposite ends, and the lower containers having upper walls providing means upwardly extending therefrom associated with the opposite ends of each of the grooves of the containers rested thereon, whereby the containers in one layer are constrained from horizontal movement relative to the next adjacent layers.

3. A pack of containers comprising a plurality of substantially rectangular containers each having substantially parallel top and bottom panels, each of said top and bottom panels providing substantially parallel equally spaced grooves longitudinally of their respective containers, said containers being stacked with their grooves in substantially right angular relation, and boss members located at the intersections of the grooves extended upwardly and downwardly into said grooves.

4. A pack of containers comprising a plurality of substantially rectangular containers each having a bottom, a top, and four sides in substantially right angular relation, said containers being arranged in side to side engagement in superimposed layers with the upper containers rested on the containers immediately therebelow, said tops and bottoms having substantially equally spaced grooves parallel to a pair of opposite sides of their respective containers and the containers being arranged with the grooves of the bottoms of the containers transversely disposed to the grooves in the tops of the containers on which they are rested whereby the grooves intersect; and boss members fitted downwardly into the grooves of the tops of the containers and upwardly into the grooves of the bottoms of the containers where said grooves intersect locking said containers into a nested pack.

5. A pack of containers comprising a plurality of substantially rectangular container units each having a bottom wall member, a top wall member, and four side wall means all interconnected in substantially right angular relation, said containers being arranged in horizontal engagement in superimposed layers with the upper containers rested on the containers immediately therebelow, the Wall members and means of said containers being of sheet material and the top and bottom wall members having substantially parallel elongated grooves therein substantially parallel to the side walls and terminating short of the end wall means of their respective containers, each of said top and bottom wall members having a male side and a female side and being of a form adapted to nest with a female side of one such wall member receiving a male side of the other, the end and side wall means marginally extending under the bottom. wall member of their respective container and marginally extending over the top wall member thereof and being secured to both, the bottom wall members of the upper containers and the upper wall members of the bottom containers having their grooves correspondingly disposed for nested engagement to resist lateral shifting of the containers, and the end wall means and the side wall means of the upper containers where they marginally extend under their bottom wall members resting on the end wall means and side wall means of the lower containers where they marginally extend over their top wall members, whereby the weight of one container relative to another thercbelow in the pack is carried by the end and side wall means of the containers.

6. In a pack of substantially rectangular sheet metal containers arranged in horizontal engagement in superimposed layers whereby there are relatively upper and lower containers, the combination of top walls for the containers substantially identical to bottom walls for the containers, said top and bottom walls each providing substantially parallel grooves having closed ends and providing concavities outwardly disposed from their respective containers, said grooves being substantially equally spaced in each of the containers and being of substantially the same transverse frustum' shape and dimensions, the upper containers being arranged with the grooves of their bottom walls superimposed and angularly related to the grooves of the top walls of the lower containers adjacent to closed end portions thereof, and boss members received in the grooves of the top walls of the lower containers where overlaid by the grooves of the bottom Walls of the upper containers and extended upwardly in fitted engagement into said overlying grooves of said bottom walls of the upper containers.

7. A pack of sheet metal containers comprising a plurality of such containers arranged in horizontal engagement in superimposed layers whereby there are relative upper and lower layers of containers, each of the containers havingopposite end walls, opposite side walls, and top and bottom walls, thetop and bottom walls of each container being substantially identical and providing elongated outwardly disposed concave grooves substantially parallel to their respective side walls and terminating short of their respective end walls, the end walls and the side walls of each container marginally extending under its respective bottom wall and marginally extending over its respective top Wall and being secured to both, the upper containers being arranged with the grooves of their bottom walls positioned over the upwardly disposed grooves of the top walls of the lower containers and with the end and side walls of the upper containers where they marginally extend beneath the bottom walls thereof being rested on the end and side walls of the lower containers where they marginally extend over the top walls thereof, and boss members rigidly secured in the grooves of the top walls of the bottom containers releasably fitted into the overlapping grooves of the bottom Walls of the upper containers.

8. The pack of claim 7 in which grooves of the bottom walls of the upper containers extend transversely of the grooves of the top walls of the lower containers in substantially right angular relation thereto.

9. A container adapted for interlocking engagement relative to a second similarly configured container when the second container is vertically adjacent the container in a stack, each container comprising a top wall member and a substantially identically configured bottom Wall member, side and end wall means connected to each of the top and bottom wall members and extending between them to define a compartment, corresponding indentations in the top and bottom wall members, the top wall member of each container being associable with its cor- 10. A container according to claim 9 wherein the side and end wall means associated with the top Wall member marginally overlie the top wall member and the side and References (Jited in the file of this patent UNITED STATES PATENTS 2,160,893 Newson June 6, 1939 2,739,734 Pugh Mar. 27, 1956 2,939,603 Young June 7, 1960 2,986,300 Parrish May 30, 1961 

1. IN A PACK OF CONTAINERS, THE COMBINATION OF A PLURALITY OF CONTAINERS STACKED IN SUPERIMPOSED LAYERS WHEREBY THERE ARE RELATIVELY UPPER AND LOWER CONTAINERS, EACH OF THE UPPER CONTAINERS HAVING A LOWER WALL SUPPORTED ON THE LOWER CONTAINERS AND PROVIDING A PAIR OF SUBSTANTIALLY PARALLEL GROOVES THEREIN, AND EACH OF THE LOWER CONTAINERS 